反応 #7105

反応方程式

3-bromo-2-fluorobenzoic acid

trimethylorthoformate

p-toluenesulfonic acid

→

methyl 3-bromo-2-fluorobenzoate

収率 84.0%

溶媒

methanol

反応条件

後処理

1. 1
   温度heated
2. 2
   温度under reflux
3. 3
   その他the mixture was evaporated
4. 4
   その他the residue partitioned between water and Et2O
5. 5
   洗浄The organic layer was washed with sat. sodium hydrogen carbonate solution, water, brine
6. 6
   乾燥dried (MgSO4)
7. 7
   その他evaporated

実験手順

A solution of 3-bromo-2-fluorobenzoic acid (0.219 g, 1 mmol) in dry methanol (5 ml) under nitrogen was treated with trimethylorthoformate (0.22 ml, 2 mmol) and p-toluenesulfonic acid (catalytic amount), and then heated under reflux. After 16 h, the mixture was evaporated and the residue partitioned between water and Et2O. The organic layer was washed with sat. sodium hydrogen carbonate solution, water, brine, dried (MgSO4) and evaporated to give methyl 3-bromo-2-fluorobenzoate (0.195 g, 0.84 mmol, 84%): 1H NMR (CDCl3) δ 7.90–7.85 (m, 1H), 7.71–7.65 (m, 1H), 7.10 (dt, 1H, J=8.0, 1.0 Hz) and 3.94 (s, 3H): MS (EI) 232 (M+).

出典